Growth and lifecycle

Method of reproduction and disperal

African boxthorn reproduces exclusively by seed which is commonly eaten by birds, seed is viable when excreted. These plants are often found near places where birds have perched such as trees, poles and powerlines. It was widely planted as a hedge plant before its weedy potential was realised. Spread also occurs from contaminated produce and materials.

Rate of growth and spread

African boxthorn is a fast growing invasive species that, if untreated, spreads quickly. Seeds may germinate year round and early root growth is rapid, ensuring young plants are competitive. Plants take at least two years to flower, producing flowers and fruit mostly in summer. Some flowering and fruit production occurs at other times of year. Sometimes deciduous in winter, with new leaves and active growth in spring. Broken roots and cut stumps can sprout regrowth.

African boxthorn is widely distributed across Victoria and most abundant in western and northern catchments.

Growth calendar

The icons on the calendar below represent the times of year for flowering, seeding, germination, the dormancy period of African boxthorn and also the optimum time for treatment.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Flowering

Seeding

Germination

Dormancy

Treatment

New Growth

Active Growth

Impact

Impact on ecosystems and waterways

If untreated, African boxthorn grows to a great size and dense infestations out-compete native plants. It invades watercourses denying animals access to water. It also provides harbour for pest animals such as rabbits and foxes.

African boxthorn provides a breeding place for pest insects such as fruit fly, dried fruit beetle, tomato fly and the house fly. It is suspected of being slightly toxic to stock although seldom grazed due to long spines. Control of established plants is expensive, often requiring heavy machinery to complete physical removal.

Social value and health impacts

Fruit of African boxthorn may be toxic to humans and its spines can inflict painful injuries. If left untreated, large plants and dense infestations can impede access by people and vehicles.

References

Following changes to the Victorian Government structure, the content on this site is in transition. There may be references to previous departments, these are being updated. Please call 136 186 to clarify any specific information.